i believe the KDDI butterly J was kept off of the official unlock program,much like the verizon DNA,and a few others. an exploit to superCID was needed in order to allow unlock.
i would prolly head to htcdev.com and try and unlock the bootloader,and see if it is successful. if so,youll just need to find,or wait for,a compatible recovery image that you can install,and then simply flash superuser root files.
if the unlock is not successful,"moonshine s-off" is coming soon for some other One variants and the DNA. maybe once its released,support could be added for the J one,so id watch the moonshine threads in the DNA and one original android root forums over on XDA